Please help in Java:

Create a main method and use these input files to test that you are able to input the Undergraduates, put them into an ArrayList, print out the list. Repeat for Graduate, Faculty, Staff. I have purposely kept the input files small so you can do it all in one main.

Then- Add a compareTo to each class (and any other code you need) so you can sort all your ArrayLists and print out the results. Your final output should be all the Undergraduates (sorted), all the Graduates (sorted), all the Faculty(sorted), and all the Staff (sorted).

To sort: Sort undergrads and grads according to ID. Sort Faculty according to Department and Staff according to Salary.

I have Lab10.java to keep main in but it is not completed, which is what im seeking help for.

I have Person.java ; Student.java ; Employee.java ; Undergraduate.java ; Graduate.java ; Faculty.java & Staff.java completed.